Organically modified clay particles and polyethylene production catalyst containing the same

Abstract

To provide novel organically modified clay particles which are suitable for a polymerization catalyst activator and a polymerization catalyst, capable of suppressing fouling during polymerization of polymers such as polyolefins represented by polyethylene and enabling efficient production of polymers having superior processability, and to provide a polyethylene production catalyst containing the same.SOLUTION: Organically modified clay particles, being particles of organically modified clay having an organic aliphatic group, wherein (a) a median diameter and a mode diameter measured by laser diffraction / scattering particle size distribution measurement are 10 μm or more and 20 μm or less, and (b) a proportion of particles of 5 μm or less and 33 μm or more measured by laser diffraction / scattering particle size distribution measurement is 5 vol.% or less, respectively.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to novel organically modified clay particles, which are expected to be useful as polymerization catalyst activators suitable for producing polyethylene, such as ultra-high molecular weight polyethylene, and polyolefins. In particular, the present invention relates to a polymerization catalyst activator that suppresses fouling and static electricity, which tend to occur during and after the polymerization of polyolefins, such as polyethylene, and is capable of producing polymers with excellent processability at high activity, and a catalyst for producing polyethylene containing the same. [Background technology]

[0002] In recent years, due to environmental concerns, automobile drive systems have been shifting from internal combustion engines to lithium-ion batteries, and demand for ultra-high molecular weight polyethylene (ULHMWPE) used as separators for lithium-ion batteries has been increasing. However, because molded bodies of ULHMWPE produced using Ziegler catalysts have insufficient mechanical strength, it has been proposed to produce ULHMWPE with a narrow molecular weight distribution using a catalyst made of a transition metal compound that is a metallocene complex (hereinafter sometimes abbreviated as a single-site catalyst) (see, for example, Patent Document 1).

[0003] Because ultra-high molecular weight polyethylene is supplied to processors as a powder, the powder properties of the polyethylene, such as bulk density, particle size, and particle size distribution, are important. In particular, if ultra-high molecular weight polyethylene particles contain a large number of fine particles, there is a risk of dust explosions, so it is necessary to reduce the proportion of fine particles as much as possible. To address these issues, catalysts consisting of metallocene complexes, spherical organically modified clays, and organoaluminum have been proposed (see, for example, Patent Document 2).

[0004] Furthermore, as polymerization catalyst activators, there have been proposed a polymerization catalyst activator that is an organically modified clay particle having a specific particle size, a specific circularity ratio, and a specific specific surface area, which enables the highly active production of ethylene polymer particles having a narrow molecular weight distribution and a narrow particle size distribution (see, for example, Patent Document 3), and a polymerization catalyst activator that is a bimodal organically modified clay particle having a specific particle size distribution (see, for example, Patent Document 4).

[0005] On the other hand, polyethylene powder is easily charged by friction, and there are concerns that it may adhere to silos or hoppers of processing machines or cause fouling on reactor walls or stirring blades during polymerization. Therefore, it has been proposed to add an antistatic agent to the catalyst before polymerization (see, for example, Patent Document 5). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-34287 [Patent Document 2] Japanese Patent Application Publication No. 2018-145402 [Patent Document 3] Japanese Patent Application Publication No. 2023-117554 [Patent Document 4] Japanese Patent Publication No. 2023-117555 [Patent Document 5] Japanese Patent Application Laid-Open No. 2017-141350 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the catalyst proposed in Patent Document 1 did not address the powder performance of the resulting ethylene polymer, and the catalyst proposed in Patent Document 2 was effective in suppressing fine particles, but left room for improvement in terms of catalytic activity, which is one aspect of catalytic performance. Furthermore, the polymerization catalyst activators proposed in Patent Documents 3 and 4 were effective in activating the polymerization catalyst, but no consideration was given to the charging and fouling of polymer particles during or after the polymerization reaction, nor to the resulting loss of productivity. Furthermore, the metallocene catalyst proposed in Patent Document 5, which contains an antistatic agent, had the problem of reduced activity.

[0008] Therefore, the present invention provides organically modified clay particles, which enable the production of polymer particles, such as polyethylene particles, that are highly active and exhibit little electrostatic adhesion during or after polymerization, and which are also expected to be used as catalyst components, as well as a polymerization catalyst. [Means for solving the problem]

[0009] As a result of extensive research to solve the above problems, the present inventors have found that organically modified clay particles having a specific particle size and particle size distribution serve as an activator for a polymerization catalyst that can efficiently produce polymer particles that are highly active, have little electrostatic adhesion, and have excellent processability, and that a catalyst for producing polyethylene that contains both a metallocene complex and an organoaluminum compound is particularly excellent, leading to the completion of the present invention.

[0010] That is, the present invention relates to organically modified clay particles having an organic aliphatic group represented by the following general formula (1) as an organic modifying group, characterized in that a) the median diameter and mode diameter, as measured by laser diffraction / scattering particle size distribution measurement, are 10 μm or more and 20 μm or less, and b) the proportion of particles having a size of 5 μm or less and 33 μm or more, as measured by laser diffraction / scattering particle size distribution measurement, are each 5 volume % or less.

[0011] [ka]

[0012] (In the formula, R 1 , R 2 , R 3 are each independently a saturated alkyl group having 1 to 30 carbon atoms, an unsaturated alkyl group having 2 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, an alkylamino group having 1 to 30 carbon atoms, an alkylsilyl group having 1 to 30 carbon atoms, an alkoxyalkylene group having 2 to 30 carbon atoms, a dialkylaminoalkylene group having 3 to 30 carbon atoms, or a trialkylsilylalkylene group having 4 to 30 carbon atoms, and R 1 , R 2 , R 3 At least one of the above is a saturated or unsaturated alkyl group having 10 or more carbon atoms, and M 1 is an atom in group 15 of the periodic table.) The present invention will be described in detail below.

[0013] The organically modified clay particles of the present invention are particles of organically modified clay modified with an organic aliphatic group represented by the above general formula (1), and are novel organically modified clay particles (hereinafter sometimes referred to as organically modified clay particles (B)) that satisfy the following requirements in the particle size distribution measured by laser diffraction / scattering particle size distribution measurement: a) median diameter and mode diameter are 10 μm or more and 20 μm or less, and b) the proportions of particles 5 μm or less and 33 μm or more are 5 volume % or less, respectively.

[0014] Here, R in the above general formula (1) 1 , R 2 , R 3 are each independently a saturated alkyl group having 1 to 30 carbon atoms, an unsaturated alkyl group having 2 to 30 carbon atoms, an alkylalkoxy group having 1 to 30 carbon atoms, an alkylamino group having 1 to 30 carbon atoms, an alkylsilyl group having 1 to 30 carbon atoms, an alkoxyalkylene group having 2 to 30 carbon atoms, a dialkylaminoalkylene group having 3 to 30 carbon atoms, or a trialkylsilylalkylene group having 4 to 30 carbon atoms, and R 1 , R 2 , R 3At least one of R is an alkyl group having 10 or more carbon atoms, and as long as the alkyl group has 10 or more carbon atoms, the alkyl group may be a saturated alkyl group or an unsaturated alkyl group. 1 , R 2 , R 3 If any of the above is an alkyl group having less than 10 carbon atoms or a substituent other than an alkyl group, it becomes difficult to efficiently produce polymer particles, such as polyethylene particles, using the resulting organically modified clay particles as an activator, and the catalyst has problems as an activator for polymerization catalysts.

[0015] And R 1 , R 2 , R 3 Specific examples of the alkyl group include saturated alkyl groups having 1 to 30 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a 2-methylbutyl group, a 1-methylbutyl group, a 1-ethylpropyl group, a neopentyl group, a tert-pentyl group, an n-hexyl group, a decyl group, a dodecyl group, a tetradecyl group, a hexadecyl group, an octadecyl group, and a behenyl group; unsaturated alkyl groups having 2 to 30 carbon atoms, such as a palymitoleyl group, an allyl group, an oleyl group, a linoleyl group, an elaidolinoleyl group, a linolenyl group, an elaidolinolenyl group, and an erucyl group; and unsaturated alkyl groups having 2 to 30 carbon atoms, such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and an isopropoxy group. alkylamino groups having 1 to 30 carbon atoms, such as a dimethylamino group, a diethylamino group, a dipropylamino group, a dibutylamino group, or a diisopropylamino group; alkylsilyl groups having 1 to 30 carbon atoms, such as a trimethylsilyl group, a tri-tert-butylsilyl group, a di-tert-butylmethylsilyl group, or a tert-butyldimethylsilyl group; alkoxyalkylene groups having 2 to 30 carbon atoms, such as a methoxymethylene group or an ethoxymethylene group; dialkylaminoalkylene groups having 3 to 30 carbon atoms, such as a dimethylaminomethylene group or a diethylaminomethylene group; and trialkylsilylalkylene groups having 4 to 20 carbon atoms, such as a trimethylsilylmethylene group or a tert-butyldimethylsilylmethylene group.

[0016] Applicable R 1 , R 2 , R 3 At least one of the substituents is an alkyl group having 10 or more carbon atoms, such as a decyl group, a dodecyl group, a tetradecyl group, a hexadecyl group, an octadecyl group, an oleyl group, or a behenyl group.

[0017] The M 1 is an atom of Group 15 of the periodic table, and if it is an atom other than Group 15 of the periodic table, it becomes difficult to efficiently produce polymer particles, such as polyethylene particles, with a catalyst using the obtained organically modified clay particles as an activator, and the catalyst has problems as an activator for a polymerization catalyst. 1 Examples of the atom include a nitrogen atom and a phosphorus atom.

[0018] Specific examples of the organic aliphatic group include aliphatic ammonium groups such as an N,N-dimethyl-behenylammonium group, an N-methyl-N-ethyl-behenylammonium group, an N-methyl-Nn-propyl-behenylammonium group, and an N,N-dioleyl-methylammonium group; and aliphatic phosphonium groups such as a P,P-dimethyl-behenylphosphonium group, a P,P-diethyl-behenylphosphonium group, and a P,P-dipropyl-behenylphosphonium group.

[0019] The clay constituting the organically modified clay particles of the present invention may be any clay as long as it falls within the category of clay. Generally, clay is formed by stacking many layers called silicate layers, which are composed of a tetrahedral sheet of silica tetrahedrons connected two-dimensionally and an octahedral sheet of alumina octahedrons or magnesia octahedrons connected two-dimensionally in a ratio of 1:1 or 2:1. The Si of some silica tetrahedrons is replaced by Al, the Al of alumina octahedrons by Mg, and the Mg of magnesia octahedrons by Li, etc., resulting in a lack of positive charge within the layers, and the layers as a whole are negatively charged. In order to compensate for this negative charge, Na is introduced between the layers. + Ya Ca 2+The clay is known to contain cations such as kaolinite, talc, smectite, vermiculite, mica, brittle mica, and mercury, both natural and synthetic, and these can be used, with smectite being preferred due to its ease of availability and ease of organic modification, and hectorite or montmorillonite being even more preferred among smectites.

[0020] The organically modified clay particles of the present invention can be obtained by modifying clay with an organic aliphatic salt represented by the following structural formula (2).

[0021] [ka]

[0022] where R 1 , R 2 , R 3 , M 1 is the same as above, and the same examples can be given. [A] - is an anion, and may be any anion as long as it belongs to the category of anions, such as fluoride ion, chloride ion, bromide ion, iodide ion, sulfate ion, nitrate ion, phosphate ion, perchlorate ion, oxalate ion, citrate ion, succinate ion, tetrafluoroborate ion, or hexafluorophosphate ion.

[0023] Specific examples of the organic aliphatic salts include aliphatic amine salts such as N,N-dimethyl-behenylamine hydrochloride, N-methyl-N-ethyl-behenylamine hydrochloride, N-methyl-Nn-propyl-behenylamine hydrochloride, N,N-dioleyl-methylamine hydrochloride, N,N-dimethyl-behenylamine sulfate, N-methyl-N-ethyl-behenylamine sulfate, N-methyl-Nn-propyl-behenylamine sulfate, and N,N-dioleyl-methylamine sulfate; and aliphatic phosphine salts such as P,P-dimethyl-behenylphosphine hydrochloride, P,P-diethyl-behenylphosphine hydrochloride, P,P-dipropyl-behenylphosphine hydrochloride, P,P-dimethyl-behenylphosphine sulfate, P,P-diethyl-behenylphosphine sulfate, and P,P-dipropyl-behenylphosphine sulfate.

[0024] The organically modified clay particles of the present invention can be obtained by introducing organic aliphatic groups between clay layers to form an ionic complex. When preparing the organically modified clay particles, it is preferable to select conditions for a clay concentration of 0.1 to 30% by weight and a treatment temperature of 0 to 100°C. The organic aliphatic salt may be prepared as a solid and dissolved in a solvent for use, or a solution of the organic aliphatic salt may be prepared by chemical reaction in a solvent and used as is. The reaction ratio of the clay to the organic aliphatic salt is optional, but it is preferable that the organic aliphatic salt be 0.5 to 1.5 mol per 1 kg of clay, as this allows for efficient organic modification. Examples of reaction solvents that can be used in the modification include aliphatic hydrocarbons such as pentane, hexane, and heptane; aromatic hydrocarbons such as benzene and toluene; alcohols such as ethyl alcohol and methyl alcohol; ethers such as ethyl ether and n-butyl ether; halogenated hydrocarbons such as methylene chloride and chloroform; acetone; 1,4-dioxane; tetrahydrofuran; and water. It is preferable to use alcohols or water alone or as one of the solvent components.

[0025] The organically modified clay particles of the present invention satisfy the following characteristics: a) median diameter and mode diameter are 10 μm or more and 20 μm or less, and b) the proportion of particles with diameters of 5 μm or less and 33 μm or more is 5% by volume or less, respectively. Here, the median diameter, mode diameter, and geometric standard deviation of particle size can be determined by measuring the particle size distribution, for example, using a laser diffraction / scattering particle size analyzer. A solvent may be used or not. If a solvent is used, a low-carbon alcohol is preferred from the viewpoint of dispersibility of the organically modified clay, and ethanol or 2-propanol is more preferred from the viewpoints of availability and ease of handling. The median diameter refers to the 50% volume cumulative diameter and is sometimes called the median diameter. The mode diameter is the particle size at the peak of the particle size distribution and is sometimes called the most frequent diameter. Although the median diameter and mode diameter have different definitions, the closer the particle size distribution approaches a lognormal distribution, the closer they become to each other. Therefore, the organically modified clay particles of the present invention, which satisfy the requirements of a) a median diameter and a mode diameter of 10 μm to 20 μm, exhibit a particle size distribution approximating a log-normal distribution. Furthermore, by satisfying the requirements of b) a ratio of particles 5 μm or less and 33 μm or more being 5 volume % or less, respectively, the ratio of fine particles and coarse particles is low. Thus, the organically modified clay particles exhibit a narrow particle size distribution approximating a log-normal distribution. Here, the activity of organically modified clay particles used as an activator for polymerization catalysts, particularly single-site catalysts, tends to be inversely proportional to the particle size of the organically modified clay particles. Therefore, in terms of high activity, it is preferable to reduce the particle size. However, on the other hand, the particle size of polymer particles, such as polyethylene powder produced using such single-site catalysts, is proportional to the particle size of the organically modified clay particles and is proportional to the cube root of the catalytic activity. Therefore, the smaller the particle size of the organically modified clay particles, the smaller the particle size of the polymer particles. This makes it more likely for the particles to adhere due to static electricity, making them less likely to fall out of silos or hoppers used during processing, and may also cause a phenomenon known as fouling on the reactor walls and agitator blades during polymerization, making it impossible to control the polymerization reaction.On the other hand, if the particle size of the organically modified clay particles is increased, not only will the activity decrease, but the organically modified clay particles remaining in the polymer particles may clog the filter of the processing machine, making it impossible to operate the processing machine for long periods of time.

[0026] Furthermore, the organically modified clay particles of the present invention have a median diameter and mode diameter of 10 μm or more and 20 μm or less, and b) the proportion of particles of 5 μm or less and 33 μm or more is 5 volume % or less, respectively, as measured by a laser diffraction / scattering particle size measuring device. Therefore, when used as an activator for polymerization catalysts, these problems are resolved, high activity is achieved, and the particles are useful as an activator for polymerization catalysts that enables the production of polymer particles that do not adhere due to static electricity or clog processing machine filters. It is particularly preferable that the difference between the median diameter and the mode diameter is within ±5 μm.

[0027] The method for producing the organically modified clay particles of the present invention is not particularly limited in terms of the method for adjusting the particle size and particle size distribution. This can be achieved by grinding, granulation, classification, or a combination of these. The grinding method is not particularly limited, and it is preferable to use so-called fine grinders, such as jet mills, bead mills, vibrating ball mills, and planetary mills, which are capable of grinding to a few micrometers. Jet mills are more preferable because they do not degrade the organically modified clay due to heat generated during grinding and allow for continuous grinding. The granulation method is also not particularly limited, and spray drying is preferred because it allows for large-scale granulation in a short period of time. Spray drying involves spraying a solution, sol, slurry, etc., and drying it with hot air to obtain particles. The spraying method is not particularly limited, and it is preferable to use a rotary atomizer, two-fluid nozzle, or four-fluid nozzle to produce fine droplets. Furthermore, the classification method is also not particularly limited, and it is preferable to use a gravity classifier, inertia classifier, centrifugal classifier, or airflow classifier from the perspective of classification accuracy. The particle size adjustment can be performed either before or after the clay is organically modified, but it is more efficient to adjust the particle size after modification, as this reduces the effect of increasing the particle size of the clay during modification.

[0028] The novel organically modified clay particles of the present invention are preferably particles modified with an organic aliphatic group represented by the general formula (1) and also containing pyrophosphate and / or etidronate as inorganic salts. Generally, when clay, particularly organically modified clay, is dispersed in water, it changes from a sol to a gel over time, losing fluidity and making it difficult to form particles. However, the inclusion of inorganic salts such as pyrophosphate and / or etidronate inhibits gelation and maintains fluidity, enabling more efficient particle formation by methods such as spray drying. In this case, alkali metal salts such as lithium salt and sodium salt are preferred as pyrophosphate and etidronate, as they have little effect on the ion exchange capacity of the organic modification. Sodium pyrophosphate and tetrasodium etidronate are even more preferred.

[0029] Clay (particles) containing pyrophosphate and / or etidronate can be prepared by dissolving pyrophosphate and / or etidronate in water and then dispersing the clay (particles), or by simultaneously adding pyrophosphate and / or etidronate and clay (particles) to water. The temperature during this process is preferably 0 to 40°C. The mixing ratio of pyrophosphate and / or etidronate to clay is preferably 1:99 to 15:85 by weight. Clays containing pyrophosphate and / or etidronate are commercially available, and these may be used as is. When clay containing inorganic salts of pyrophosphate and / or etidronate is organically modified, these inorganic salts are incorporated into the organically modified clay, and are hardly eluted even when dispersed in water. The proportion of pyrophosphate and / or etidronate in the organically modified clay is preferably 0.1% by weight or more and 10% by weight or less.

[0030] The organically modified clay particles of the present invention are suitable as a polymerization catalyst activator when producing polymers, particularly polyolefin particles such as polyethylene particles, which are polymer particles. When used as a polymerization catalyst activator, they not only achieve high activity, but also make it possible to provide a polymerization catalyst that is excellent in preventing static electricity and fouling during and after polymerization.

[0031] The polymerization catalyst to which the organically modified clay particles of the present invention are applied as a polymerization catalyst activator may be any so-called polymerization catalyst, and examples thereof include catalysts for polymerizing polyolefins such as polyethylene and polypropylene, and catalysts for producing polyethylene that exhibit particularly excellent activity. For example, a polymerization catalyst activator that functions as a polymerization catalyst when combined with a transition metal compound is preferred. Among these, a single-site polymerization catalyst combined with a transition metal compound that is a metallocene compound is preferred, as it provides a polymerization catalyst that is particularly highly active and can produce polyethylene particles with a narrow molecular weight distribution and a narrow particle size distribution with few fine particles.

[0032] Among these, transition metal compounds (A) represented by the following general formula (3) or (4):

[0033] [ka]

[0034] [ka]

[0035] [In the formula, M 2 and M 3represents a titanium atom, a zirconium atom, or a hafnium atom; each X is independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkylamino group having 1 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an alkoxyalkylene group having 2 to 20 carbon atoms, a dialkylaminoalkylene group having 3 to 20 carbon atoms, or a trialkylsilylalkylene group having 4 to 20 carbon atoms; R 4 and R 7 is a cyclopentadienyl group represented by the following general formula (5) or an indenyl group represented by the following general formula (6),

[0036] [ka]

[0037] [ka]

[0038] (In the formula, R 9 ~R 12 and R 13 ~R 18 are each independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, an alkylamino group having 1 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an alkoxyalkylene group having 2 to 20 carbon atoms, a dialkylaminoalkylene group having 3 to 20 carbon atoms, or a trialkylsilylalkylene group having 4 to 20 carbon atoms. R 5 and R 8 is an indenyl group represented by the above general formula (6) or a fluorenyl group represented by the following general formula (7),

[0039] [ka]

[0040] (In the formula, R 19 ~R 26are each independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, an alkylamino group having 1 to 20 carbon atoms, an arylamino group having 6 to 30 carbon atoms, an arylalkylamino group having 7 to 30 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an alkoxyalkylene group having 2 to 20 carbon atoms, a dialkylaminoalkylene group having 3 to 20 carbon atoms, or a trialkylsilylalkylene group having 4 to 20 carbon atoms. R 6 is R represented by the following general formula (8) or the following general formula (9): 4 and R 5 is a crosslinking unit of

[0041] [ka]

[0042] [ka]

[0043] (In the formula, R 27 ~R 28 and R 29 ~R 30 are each independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 30 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkylamino group having 1 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an alkoxyalkylene group having 2 to 20 carbon atoms, a dialkylaminoalkylene group having 3 to 20 carbon atoms, or a trialkylsilylalkylene group having 4 to 20 carbon atoms; M 4 is a silicon atom, a germanium atom, or a tin atom. l is an integer from 1 to 5. The catalyst for producing polyethylene is preferably a single-site catalyst containing the organically modified clay particles (B) of the present invention and the organoaluminum compound (C).

[0044] In this case, the transition metal compound (A) represented by the above general formula (3) or (4) is a metallocene compound, and R 4 and R 5 a cyclopentadienyl or indenyl group and R7 and R 8 Indenyl or fluorenyl group of M 2 or M 3 The structure sandwiches the R 6 By R 4 and R 5 It has a structure in which the above is cross-linked.

[0045] where M 2 and M 3 is a titanium atom, a zirconium atom, or a hafnium atom, and is preferably a zirconium atom or a hafnium atom because these specific metal atoms enable efficient production of polyolefins, particularly ethylene polymers, and provide a catalyst for polyethylene production that is particularly capable of efficiently producing high-molecular-weight polyethylene.

[0046] Each X is independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 30 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkylamino group having 1 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an alkoxyalkylene group having 2 to 20 carbon atoms, a dialkylaminoalkylene group having 3 to 20 carbon atoms, or a trialkylsilylalkylene group having 4 to 20 carbon atoms. These specific substituents make it possible to produce polyethylene particles with extremely high molecular weights. Specific examples of X include a hydrogen atom, a halogen atom such as a chlorine atom, a bromine atom, or an iodine atom; an alkyl group having 1 to 30 carbon atoms such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, or an isomeric substituent thereof; an aryl group having 6 to 30 carbon atoms such as a phenyl group, an indenyl group, a naphthyl group, a fluorenyl group, or a biphenylenyl group; an arylalkyl group having 7 to 30 carbon atoms such as a benzyl group, a phenylethyl group, a diphenylmethyl group, or a diphenylethyl group; an alkylaryl group having 7 to 30 carbon atoms such as a methylphenyl group, an ethylphenyl group, or a methylnaphthyl group; and an alkylsilyl group such as a trimethylsilyl group.

[0047] R 4 and R 7is a cyclopentadienyl group represented by the above general formula (5) or an indenyl group represented by the above general formula (6), and R 9 ~R 12 and R 13 ~R 18 are each independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, an alkylamino group having 1 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an alkoxyalkylene group having 2 to 20 carbon atoms, a dialkylaminoalkylene group having 3 to 20 carbon atoms, or a trialkylsilylalkylene group having 4 to 20 carbon atoms, and these specific substituents make it possible to produce polyethylene. 9 ~R 12 and R 13 ~R 18 Specific examples of X include the same as those listed above, and R 4 and R 7 Specific examples of the cyclopentadienyl group include a cyclopentadienyl group, a methylcyclopentadienyl group, an ethylcyclopentadienyl group, an n-butylcyclopentadienyl group, a dimethylcyclopentadienyl group, a diethylcyclopentadienyl group, a methoxycyclopentadienyl group, a dimethylaminocyclopentadienyl group, a trimethylsilylcyclopentadienyl group, an indenyl group, a methylindenyl group, a dimethylindenyl group, and a trimethylindenyl group.

[0048] R 5 and R 8 is an indenyl group represented by the general formula (6) or a fluorenyl group represented by the general formula (7), and R 13 ~R 18 and R 19 ~R 26 R are each independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, an alkylamino group having 1 to 20 carbon atoms, an arylamino group having 6 to 30 carbon atoms, an arylalkylamino group having 7 to 30 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an alkoxyalkylene group having 2 to 20 carbon atoms, a dialkylaminoalkylene group having 3 to 20 carbon atoms, or a trialkylsilylalkylene group having 4 to 20 carbon atoms. 19 ~R26 Specific examples of R 9 ~R 12 and R 13 ~R 18 Examples similar to those of R 5 and R 8 Specific examples of R include an indenyl group, a methylindenyl group, a dimethylindenyl group, a trimethylindenyl group, a fluorenyl group, a 2-methylfluorenyl group, a 2,7-dimethylfluorenyl group, a 2-dimethylaminofluorenyl group, a 2-diethylaminofluorenyl group, a 2,7-bis(diethylamino)-fluorenyl group, a 2-methoxyfluorenyl group, and a 2,7-dimethoxyfluorenyl group. 19 ~R 26 When any one of the above is an alkylamino group having 1 to 20 carbon atoms, an arylamino group having 6 to 30 carbon atoms, or an arylalkylamino group having 7 to 30 carbon atoms, an ultra-high molecular weight ethylene polymer having a molecular weight of 1,000,000 or more can be efficiently produced.

[0049] R 6 is the R 4 and the R 5 is a crosslinking unit represented by the general formula (8) or the general formula (9), and R 27 ~R 28 and R 29 ~R 30 are each independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 30 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkylamino group having 1 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an alkoxyalkylene group having 2 to 20 carbon atoms, a dialkylaminoalkylene group having 3 to 20 carbon atoms, or a trialkylsilylalkylene group having 4 to 20 carbon atoms, and these specific substituents make it possible to produce an ethylene polymer having a high molecular weight. 27 ~R 28 and R 29 ~R 30 Specific examples of include the same as the examples of X given above.

[0050] and l is an integer from 1 to 5.

[0051] The transition metal compound (A) is a metallocene compound having a ligand structure combining a cyclopentadienyl group and an indenyl group, a cyclopentadienyl group and a fluorenyl group, two indenyl groups, or an indenyl group and a fluorenyl group, and specific examples thereof include cyclopentadienyl(indenyl)zirconium dichloride, methylenecyclopentadienyl(indenyl)zirconium dichloride, ethylenecyclopentadienyl(indenyl)zirconium dichloride, isopropylenecyclopentadienyl(indenyl)zirconium dichloride, diphenylmethylenecyclopentadienyl(indenyl)zirconium Dichloride, bisindenyl zirconium dichloride, methylene bisindenyl dichloride, ethylene bisindenyl dichloride, diphenylmethylene bisindenyl dichloride, cyclopentadienyl(9-fluorenyl)zirconium dichloride, diphenylmethylene(cyclopentadienyl)(9-fluorenyl)zirconium dichloride, dimethylsilane(cyclopentadienyl)(9-fluorenyl)zirconium dichloride, diphenylmethylene(cyclopentadienyl)(2-(dimethylamino)-9-fluorenyl)zirconium dichloride, diphenylmethylene(cyclopentadienyl)(2,7-bis(dimethylamino)-9-fluorenyl)zirconium dichloride, (2-methylamino-9-fluorenyl)zirconium dichloride, indenyl(fluorenyl)zirconium dichloride, ethylene(indenyl)(9-fluorenyl)zirconium dichloride, diphenylmethylene(indenyl)(9-fluorenyl)zirconium dichloride, diphenylmethylene(indenyl)(2-dimethylamino-9-fluorenyl)zirconium dichloride, diphenylmethylene(indenyl)(2 Examples include zirconium compounds such as (-methyl-9-fluorenyl)zirconium dichloride, compounds in which the zirconium atom is replaced with a titanium atom or a hafnium atom, and compounds in which the dichloro form of the above metallocene compounds is replaced with a dimethyl form, a diethyl form, a dihydro form, a diphenyl form, or a dibenzyl form. Among these, zirconium-based compounds and hafnium-based compounds are preferred because they serve as catalysts for polyethylene production that can efficiently produce polyethylene and high-molecular-weight ethylene copolymers.

[0052] The organoaluminum compound (C) can be any compound that falls into the category of organoaluminum compounds, and among these, an organoaluminum compound represented by the following general formula (10) is preferred because it serves as a catalyst for polyethylene production that enables efficient production of ultra-high molecular weight polyethylene particles. Furthermore, compounds other than organoaluminum compounds, such as boron-based compounds and methylalumoxane-based compounds, may also be used, but this is not intended to limit their use, as long as they exhibit the effect of a polymerization catalyst.

[0053] [ka]

[0054] (In the formula, R 31 is a hydrocarbon group having 1 to 20 carbon atoms, and R 32 and R 33 are each independently a hydrocarbon group having 1 to 20 carbon atoms, a hydrogen atom, or a chlorine atom. As the organoaluminum compound, in particular, alkylaluminum such as trimethylaluminum, triethylaluminum, triisobutylaluminum, etc. can be mentioned, since it enables easy alkylation of the transition metal compound (A).

[0055] Furthermore, when used as a polymerization catalyst, particularly as a catalyst for producing polyethylene, it may contain a nonionic surfactant (D) represented by the following general formula (11).

[0056] [ka]

[0057] Here, a, b, and c each represent an average degree of polymerization and are integers of 1 to 300, preferably a and c each are integers of 1 to 60, b is an integer of 2 to 100, and the total molecular weight is preferably 100 to 20,000. Furthermore, m is 1 or 2, and n is an integer of 3 to 20, preferably m is 2 and n is 3.

[0058] Specific examples of the nonionic surfactant (D) include polyoxymethylene polyoxypropylene glycol, polyoxyethylene polyoxypropylene glycol, and the like.

[0059] Addition of the nonionic surfactant (D) makes the resulting polymer particles, for example, polyethylene particles typified by polyolefin particles, even less likely to become electrically charged, which is highly effective in suppressing fouling in the reactor and preventing a decrease in fluidity due to electrostatic adhesion.

[0060] The proportions of the transition metal compound (A) (hereinafter sometimes referred to as component (A)), the organically modified clay particles (B) (hereinafter sometimes referred to as component (B)), and the organoaluminum compound (C) (hereinafter sometimes referred to as component (C)) used in constructing a catalyst for polyethylene production are not subject to any limitations as long as they are usable as a catalyst for polyethylene production. To achieve a catalyst capable of efficiently producing polyethylene particles, the molar ratio of component (A) to component (C) per metal atom is preferably (component (A)):(component (C)) = 100:1 to 1:100,000, and more preferably 1:1 to 1:10,000. Furthermore, the weight ratio of component (A) to component (B) is preferably (component (A)):(component (B)) = 10:1 to 1:10,000, and more preferably 3:1 to 1:1,000.

[0061] Furthermore, the weight ratio of the nonionic surfactant (D) (hereinafter sometimes referred to as component (D)) used is preferably in the range of (component (B)):(component (D))=1:0.0001 to 1:100, and particularly preferably in the range of (component (B)):(component (D))=1:0.01 to 20, because this provides excellent antistatic properties and polymerization activity.

[0062] Any method for preparing a catalyst for polyethylene production may be used as long as it allows preparation from the component (A), the component (B), and the component (C). Examples include a method in which components (A), (B), and (C) are mixed in an inert solvent or using ethylene, which is to be polymerized, as a solvent. There is no restriction on the order in which these components are reacted. Because of their particularly excellent polymerization activity, it is preferable to contact the component (B) and the component (C) first, and then the component (A) to obtain a catalyst for polyethylene production. There are no restrictions on the temperature or duration of this treatment. It is also possible to prepare a catalyst for polyethylene production using two or more types of each of the component (A), component (B), and component (C).

[0063] The resulting polymer, polyethylene, may be not only a homopolymer of ethylene but also a copolymer with other α-olefins, and the polyethylene obtained by these polymerizations is used to include not only homopolymers but also copolymers.

[0064] A method for producing polyethylene includes a slurry polymerization method. The solvent used in the slurry polymerization method may be any commonly used organic solvent, such as benzene, toluene, xylene, pentane, hexane, or heptane. Olefins such as propylene, 1-butene, 1-octene, or 1-hexene can also be used as the solvent.

[0065] Examples of the α-olefin to be used for copolymerization with ethylene to produce polyethylene include α-olefins such as propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, and 1-octene.

[0066] When producing polyethylene using the catalyst for polyethylene production, polymerization conditions such as polymerization temperature, polymerization time, polymerization pressure, and monomer concentration can be selected as desired. Among these, it is preferable to carry out the polymerization at a temperature of 30 to 90°C, for a polymerization time of 10 seconds to 20 hours, and at a polymerization pressure in the range of atmospheric pressure to 100 MPa, since this enables efficient production of polyethylene particles. It is also possible to adjust the molecular weight using hydrogen or the like during polymerization. The polymerization can be carried out by any of batch, semi-continuous, and continuous methods, and can also be carried out in two or more stages by changing the polymerization conditions. The polyethylene particles obtained after polymerization can be separated and recovered from the polymerization solvent by known methods and dried.

[0067] The novel organically modified clay particles of the present invention are expected to be used as an activator for polymerization catalysts for ethylene, propylene, and even α-olefins. Polymerization catalysts containing the organically modified clay particles as an activator have excellent productivity in the production of polyolefins, and in particular, catalysts for the production of ethylene suppress charging and fouling during the polymerization of polyethylene, making it possible to efficiently produce polyethylene with excellent processability. [Effects of the Invention]

[0068] The present invention provides a polymerization catalyst activator that suppresses fouling during polymerization of polyolefins, such as polyethylene, and enables efficient production of polymers with excellent processability; novel organically modified clay particles suitable for polymerization catalysts; and a catalyst for producing polyethylene containing the same. [Example]

[0069] The present invention will be described in more detail below by showing examples, but the present invention is not limited to these examples.

[0070] The preparation and evaluation methods used in the examples and comparative examples are shown below.

[0071] -Crush- The mixture was pulverized using an airflow pulverizer (manufactured by Nisshin Engineering, product name SJ-1500CB) at a feed rate of 20 kg / hr and a pulverization pressure of 0.5 to 0.7 MPa.

[0072] -Granulation (spray drying)- Using a spray dryer (manufactured by IS Japan, product name SDR-27), the clay sol was sprayed at a disk rotation speed of 24,000 rpm and spray-dried with the hot air inlet temperature set to 300°C.

[0073] -Classification- An airflow classifier (manufactured by Nisshin Engineering, product name TC-25) was used, with a supply rate of 20 kg / hr and an air volume of 7.5 m 3 Classification was carried out by adjusting the rotation speed.

[0074] -Calculating the percentage of inorganic salts- The sample was coated with conductive osmium, and then subjected to EDS elemental analysis (manufactured by JEOL Ltd., (product name) FE-SEM JSM-7100F / EDS JED-2300) at an acceleration voltage of 15 kV. The weight ratios of carbon, silicon, and phosphorus were calculated.

[0075] -Measurement of moisture content- Measurement was carried out using an infrared moisture meter (manufactured by Kett Electric Laboratory, (trade name) FD-610).

[0076] -Measurement of particle size distribution- A laser diffraction / scattering particle size distribution analyzer (Microtrac-Bell, product name MT-3300) was used, and 2-propanol was used as the solvent. From the particle size distribution obtained, the median diameter, mode diameter, and particle size ratio were obtained.

[0077] Example 1 (1) Manufacturing of organically modified clay particles A 5L beaker was charged with 319.2g of dioleylmethylamine (Lion Specialty Chemicals, trade name: Lipomin MO), 1.8L of water, and 1.8L of industrial alcohol (Japan Alcohol Sales, trade name: Ekinen F-3). The mixture was heated with stirring to 40°C, and 63.5mL of 35% hydrochloric acid was slowly added to obtain a homogeneous solution. The homogeneous solution was then heated to 60°C, and 639.7g of 6.2% water hectorite (BYK Japan, trade name: Laponite RD) was added. The mixture was stirred at 60°C for 1 hour to obtain a slurry. The slurry was filtered, washed twice with 1.8L of water, and dried at 85°C for 24 hours to obtain an organically modified clay. By pulverizing this organically modified clay using a jet mill and classifying it using an air classifier (removing fine powder and coarse powder), 312 g of organically modified clay particles were obtained, with a median diameter of 14.4 μm, a mode diameter of 15.6 μm, a proportion of particles below 5 μm of 4.8% by volume, and a proportion of particles above 33 μm of 1.2% by weight.

[0078] (2) Production of polymerization catalyst A 300 ml flask with nitrogen purging was charged with 20.0 g of the organically modified clay particles obtained in (1) as a polymerization catalyst activator, 87 ml of n-hexane, and 114 ml of 20 wt % triisobutylaluminum hexane solution, and stirred for 1 hour. 313.9 mg of bisindenylzirconium dichloride, a transition metal compound (metallocene compound), was then added, and the mixture was stirred at 60°C for 3 hours. After allowing to stand at room temperature for 1 hour, the supernatant was removed and diluted with 1 wt % triisobutylaluminum hexane solution to obtain 200 ml of polymerization catalyst slurry.

[0079] (3) Production of polyethylene particles A 2-liter pressure vessel was purged with nitrogen and charged with 1.2 liters of n-hexane, 1.1 ml of a 20 wt. % triisobutylaluminum hexane solution, and the catalyst slurry (prepared in (2)) equivalent to 19.4 mg of solids. Ethylene was continuously supplied to the vessel at a partial pressure of 0.90 MPa while maintaining the vessel temperature at 85°C. After 90 minutes, the vessel was depressurized and cooled. The slurry was filtered and dried, yielding 157 g of polyethylene (activity: 8100 g / g catalyst). After polymerization, no polyethylene adhered to the vessel walls or the stirring blades. The resulting granular polyethylene could be poured into the hopper of the processing machine without adhering to the vessel.

[0080] Example 2 (1) Production of clay containing inorganic salts Internal volume 1m 3 A stainless steel container was charged with 600 kg of water and 4.8 kg of sodium pyrophosphate decahydrate (Fujifilm Wako Pure Chemical Industries, Ltd.) as an inorganic salt, and the mixture was thoroughly stirred to form a homogeneous solution. Then, 40.5 kg of hectorite with a water content of 6.2 wt% was gradually added to form a sol. This sol was spray-dried to granulate the clay, and then classified (fine and coarse particles were removed) to obtain 21.0 kg of clay particles containing inorganic salts. The clay particles had a median diameter of 11.8 μm, a mode diameter of 12.0 μm, 0.2 vol% of particles smaller than 5 μm, and 0 vol% of particles larger than 33 μm. The water content of these clay particles was 8.0 wt%.

[0081] (2) Manufacturing of organically modified clay particles A 5-liter beaker was charged with 269.5 g of behenyldimethylamine (Lipomin DM22D, manufactured by Lion Specialty Chemicals), 1.8 L of water, and 1.8 L of industrial alcohol. The mixture was heated with stirring to 40°C, and 80.7 mL of 35% hydrochloric acid was slowly added to form a homogeneous solution. After heating the homogeneous solution to 60°C, 650 g of clay particles containing inorganic salts obtained in Example 2(1) was added and stirred at 60°C for 1 hour to form a slurry. The slurry was filtered, washed twice with 1.8 L of water, and dried at 85°C for 24 hours to obtain 841 g of organically modified clay particles with a median diameter of 13.3 μm, a mode diameter of 14.3 μm, 2.0 vol% of particles smaller than 5 μm, and 0.4 vol% of particles larger than 33 μm. The weight percentage of sodium pyrophosphate in the organically modified clay particles was 4.8 wt%.

[0082] (3) Production of polymerization catalyst A polymerization catalyst slurry was obtained in the same manner as in (2) of Example 1, except that the organically modified clay particles were the organically modified clay particles obtained in (2) of Example 2, and the transition metal compound was 479.7 mg of diphenylmethylene(cyclopentadienyl)(2-(dimethylamino)-9-fluorenyl)zirconium dichloride, a metallocene compound.

[0083] (4) Production of polyethylene particles A 10 L small pressure vessel was purged with nitrogen and charged with 6.0 L of n-hexane, 5.5 ml of a 20 wt % triisobutylaluminum hexane solution, and the polymerization catalyst slurry obtained in Example 2(3) (equivalent to 240 mg of solids). While maintaining the temperature inside the pressure vessel at 60°C, ethylene was continuously supplied for 40 minutes to maintain a partial pressure of 0.87 MPa. Subsequently, ethylene and hydrogen were continuously supplied for 260 minutes to maintain an ethylene partial pressure of 0.37 MPa and a hydrogen concentration of 30,000 ppm. Slurry polymerization was carried out. After polymerization, the vessel was depressurized and cooled. The slurry was filtered and dried, yielding 1,563 g of polyethylene (activity: 6,500 g / g catalyst). No polyethylene adhered to the walls or agitator blades of the pressure vessel after polymerization, and the resulting granular polyethylene could be poured entirely into the hopper of the processing machine without adhering to the vessel.

[0084] Example 3 (1) Production of clay containing inorganic salts The same procedure as in Example 2(1) was repeated except that the weight of hectorite was 20.0 kg. 8.9 kg of inorganic salt-containing clay particles were obtained. The median diameter was 10.3 μm, the mode diameter was 11.0 μm, the proportion of particles smaller than 5 μm was 1.4 vol.%, and the proportion of particles larger than 33 μm was 0 vol.%. The moisture content of this inorganic salt-containing clay was 8.7 wt.%.

[0085] (2) Manufacturing of organically modified clay particles The same procedure as in Example 2(2) was carried out except that 660 g of clay particles containing inorganic salts synthesized in (1) was used, resulting in 841 g of organically modified clay particles as an activator for polymerization catalysts, with a median diameter of 11.6 μm, a mode diameter of 12.0 μm, a proportion of particles 5 μm or less of 3.0 vol%, and a proportion of particles 33 μm or more of 0 vol%. The proportion of sodium pyrophosphate in the organically modified clay particles was 9.1 wt%.

[0086] (3) Preparation of polymerization catalyst A polymerization catalyst slurry was obtained by the same procedure as in (2) of Example 1, except that the organically modified clay particles were the organically modified clay particles obtained in (2) of Example 3, and the transition metal compound was 572.0 mg of the metallocene compound diphenylmethylene(cyclopentadienyl)(2-(dimethylamino)-9-fluorenyl)hafnium dichloride.

[0087] (4) Polyethylene production A 2-liter pressure vessel was purged with nitrogen and charged with 1.2 liters of n-hexane, 1.1 ml of a 20 wt. % triisobutylaluminum hexane solution, and the catalyst slurry (prepared in (3)) equivalent to 48.9 mg of solids. Ethylene was continuously supplied to the vessel at a partial pressure of 0.78 MPa while maintaining the vessel temperature at 70°C. After 108 minutes, the vessel was depressurized and cooled. The slurry was filtered and dried, yielding 211 g of polyethylene (activity: 4300 g / g catalyst). After polymerization, no polyethylene adhered to the vessel walls or the stirring blades. The resulting granular polyethylene could be poured into the hopper of the processing machine without adhering to the vessel.

[0088] Example 4 (1) Production of clay containing inorganic salts A 500 L stainless steel vessel was charged with 100 kg of water and 4.8 kg of 60% 1-hydroxyethane-1,1-bisphosphonic acid solution (Fujifilm Wako Pure Chemical Industries, Ltd.). While thoroughly stirring, 55.92 L of 5.0 N sodium hydroxide solution was slowly added to prepare an aqueous solution of tetrasodium etidronate. 40.3 kg of hectorite with a water content of 6.2 wt% was gradually added to this solution to form a sol. This sol was spray-dried to granulate the clay, followed by classification (fine and coarse particles removed), yielding 22.2 kg of inorganic salt-containing clay particles with a median diameter of 12.4 μm, a mode diameter of 13.8 μm, 4.2 vol% of particles below 5 μm, and 1.5 vol% of particles above 33 μm. The water content of this inorganic salt-containing clay was 8.4 wt%.

[0089] (2) Manufacturing of organically modified clay particles The same procedure as in Example 2(2) was carried out except that 660 g of inorganic clay particles synthesized in (1) was used, resulting in 850 g of organically modified clay particles as an activator for polymerization catalysts, with a median diameter of 14.6 μm, a mode diameter of 15.6 μm, a proportion of particles 5 μm or less of 3.9 vol%, and a proportion of particles 33 μm or more of 2.0 vol%. The proportion of tetrasodium etidronate in the organically modified clay particles was 6.8 wt%.

[0090] (3) Production of polymerization catalyst A 300 ml flask purged with nitrogen was charged with 25.0 g of the organically modified clay particles obtained in Example 4(2), 108 ml of n-hexane, and 142 ml of 20 wt % triisobutylaluminum hexane solution, and the mixture was stirred for 1 hour. 612.7 mg of diphenylmethylene(cyclopentadienyl)(2-(t-butyl)-9-fluorenyl)zirconium dichloride, a metallocene compound, was added as a transition metal compound, and the mixture was stirred at 60°C for 3 hours. After allowing to stand at room temperature for 1 hour, the supernatant was removed and diluted with 1 wt % triisobutylaluminum hexane solution to obtain 250 ml of polymerization catalyst slurry.

[0091] (4) Polyethylene production A 10 L pressure vessel was purged with nitrogen and charged with 6.0 L of n-hexane, 5.5 mL of a 20 wt% triisobutylaluminum hexane solution, and the catalyst slurry (prepared in step (3)) equivalent to 261 mg of solids. While maintaining the temperature at 60 °C, ethylene was continuously supplied for 70 minutes to maintain a partial pressure of 0.87 MPa. Slurry polymerization was then carried out by continuously supplying ethylene and hydrogen for 230 minutes to maintain an ethylene partial pressure of 0.87 MPa and a hydrogen concentration of 4500 ppm. After polymerization, the vessel was depressurized and cooled. The slurry was filtered and dried, yielding 1820 g of polyethylene (activity 7000 g / g catalyst). There was no adhesion of polyethylene to the vessel walls or the stirring blades, and the resulting granular polyethylene could be poured into the hopper of the processing machine without adhering to the vessel.

[0092] Example 5 (1) Clay classification 5.0 kg of montmorillonite (Kunipia F, product name, manufactured by Kunimine Industries Co., Ltd.) was crushed and classified (fine powder and coarse powder removed) to obtain 1.2 kg of classified montmorillonite with a median diameter of 16.7 μm, a mode diameter of 17.0 μm, a proportion of 5 μm or less of 3.4 vol%, and a proportion of 33 μm or more of 1.8 vol%. The moisture content of this classified montmorillonite was 7.2%.

[0093] (2) Manufacturing of organically modified clay particles A 5-liter beaker was charged with 212.2 g of behenyldimethylamine, 1.8 L of water, and 1.8 L of industrial alcohol (manufactured by Japan Alcohol Sales Co., Ltd., trade name: Equinene F-3). The mixture was heated with stirring to 40°C, and 63.5 mL of 35% hydrochloric acid was slowly added to obtain a homogeneous solution. After heating the homogeneous solution to 60°C, 646.6 g of the classified montmorillonite obtained in (1) was added and stirred at 60°C for 1 hour to obtain a slurry. The slurry was filtered, washed twice with 1.8 L of water, and dried at 85°C for 24 hours to obtain 794 g of organically modified clay particles as a polymerization catalyst activator. The particles had a median diameter of 18.8 μm, a mode diameter of 18.5 μm, a proportion of particles less than 5 μm (2.7%), and a proportion of particles greater than 33 μm (4.0%).

[0094] (3) Preparation of polymerization catalyst A polymerization catalyst slurry was obtained in the same manner as in Example 4(3), except that the organically modified clay particles were the organically modified clay particles obtained in Example 5(2).

[0095] (4) Polyethylene production A 10 L small pressure vessel was purged with nitrogen and charged with 6.0 L of n-hexane, 5.5 ml of a 20 wt % triisobutylaluminum hexane solution, and the polymerization catalyst slurry obtained in Example 5(3) (solids content: 256 mg). While maintaining the temperature inside the pressure vessel at 60°C, ethylene was continuously supplied for 85 minutes to maintain a partial pressure of 0.87 MPa. Subsequently, ethylene and hydrogen were continuously supplied for 295 minutes to maintain an ethylene partial pressure of 0.87 MPa and a hydrogen concentration of 4500 ppm. Slurry polymerization was carried out. After polymerization, the vessel was depressurized and cooled. The slurry was filtered and dried, yielding 1725 g of polyethylene (activity: 6700 g / g catalyst). No polyethylene adhered to the walls or agitator blades of the pressure vessel after polymerization, and the resulting granular polyethylene could be poured entirely into the hopper of the processing machine without adhering to the vessel.

[0096] Comparative Example 1 (1) Production of clay particles By performing the same operation as in (1) of Example 1, except that coarse particles were not removed during classification, 435 g of organically modified clay particles were obtained, with a median diameter of 29.7 μm, a mode diameter of 31.1 μm, a proportion of particles below 5 μm by volume of 0%, and a proportion of particles above 33 μm by volume of 36.8%.

[0097] (2) Preparation of catalyst A catalyst slurry was obtained in the same manner as in Example 1(2), except that the clay particles were the clay particles obtained in Comparative Example 1(1).

[0098] (3) Polyethylene production The same procedure as in Example 1(3) was carried out, except that the catalyst slurry was the catalyst slurry obtained in Comparative Example 1(2), to obtain 39 g of polyethylene (activity 2000 g / g-catalyst). The catalytic activity was low.

[0099] Comparative Example 2 (1) Production of clay containing inorganic salts Internal volume 1m 3800 kg of water and 0.96 kg of sodium pyrophosphate decahydrate were placed in a stainless steel container and thoroughly stirred to form a homogeneous solution. 8.1 kg of hectorite with a moisture content of 6.2 wt% was then added in small portions to form a sol. This sol was spray-dried to granulate the clay, which was then classified (removal of coarse particles only) to obtain 3.9 kg of clay particles containing inorganic salts. The clay had a median diameter of 7.9 μm, a mode diameter of 8.5 μm, 8.4 vol% of particles below 5 μm, and 0 vol% of particles above 33 μm. The moisture content of this clay containing inorganic salts was 8.5 wt%.

[0100] (2) Synthesis of organically modified clay By carrying out the same procedure as in (2) of Example 2, except that 660 g of the clay containing inorganic salt obtained in (1) was used, 849 g of organically modified clay was obtained, which had a median diameter of 9.3 μm, a mode diameter of 10.1 μm, a proportion of particles less than 5 μm of 7.8 vol%, and a proportion of particles greater than 33 μm of 0 vol%. The proportion of sodium pyrophosphate contained in this organically modified clay was 4.8 wt%.

[0101] (3) Catalyst production A catalyst slurry was obtained by the same procedure as in Example 2(3), except that the organically modified clay obtained in Comparative Example 2(2) was used.

[0102] (4) Polyethylene production The same procedure as in Example 2(4) was carried out, except that the catalyst slurry obtained in Comparative Example 2(3) was used, to obtain 650 g of polyethylene (activity 2700 g / g-catalyst). In addition to low catalytic activity, a large amount of polyethylene adhered to the vessel wall and stirring blades of the open small pressure vessel, and when the recovered polyethylene in particulate form was charged into the hopper of the processing machine, a large amount of polyethylene adhered to the inside of the hopper.

[0103] Comparative Example 3 (1) Production of clay containing inorganic salts By carrying out the same procedure as in Example 4(1), except that 25.0 kg of hectorite and 100 kg of water were used, 23.4 kg of clay containing inorganic salts was obtained, with a median diameter of 8.3 μm, a mode diameter of 7.8 μm, 16.8 vol% of particles 5 μm or less, and 1.0 vol% of particles 33 μm or more. The water content of this clay containing inorganic salts was 8.5 wt%.

[0104] (2) Manufacturing of organically modified clay The same procedure as in Example 4(2) was carried out except that the clay containing inorganic salt obtained in Comparative Example 3(1) was used, and 850 g of organically modified clay was obtained. The median diameter was 12.2 μm, the mode diameter was 15.6 μm, the proportion of particles 5 μm or less was 9.0 vol%, and the proportion of particles 33 μm or more was 5.7 vol%. The proportion of tetrasodium etidronate in this organically modified clay was 10.3 wt%.

[0105] (3) Catalyst production A catalyst slurry was obtained by the same procedure as in Example 4(3), except that the organically modified clay obtained in Comparative Example 3(2) was used.

[0106] (4) Polyethylene production The same procedure as in Example 4(4) was carried out, except that the catalyst slurry obtained in Comparative Example 3(3) was used, to obtain 152 g of polyethylene (activity 580 g / g-catalyst). The catalytic activity was low. Furthermore, a large amount of polyethylene adhered to the vessel wall and stirring blades of the open small pressure vessel, and when the recovered polyethylene in particulate form was introduced into the hopper of the processing machine, a large amount of polyethylene adhered to the inside of the hopper. [Industrial Applicability]

[0107] The novel modified clay particles of the present invention are suitable as a polymerization catalyst activator and polymerization catalyst that suppresses fouling during polymerization of polyolefins, such as polyethylene, and enables efficient production of polymers with excellent processability, and are therefore of extremely high industrial value.

Claims

1. The organically modified clay particles have an organic aliphatic group represented by the following general formula (1) as an organic modifying group, characterized in that a) the median diameter and mode diameter measured by laser diffraction / scattering particle size distribution measurement are 10 μm or more and 20 μm or less, and b) the proportion of particles of 5 μm or less and 33 μm or more measured by laser diffraction / scattering particle size distribution measurement are each 5 volume % or less. 【Chemical 1】 (In the formula, R １ , R ２ , R ３ are each independently a saturated alkyl group having 1 to 30 carbon atoms, an unsaturated alkyl group having 2 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, an alkylamino group having 1 to 30 carbon atoms, an alkylsilyl group having 1 to 30 carbon atoms, an alkoxyalkylene group having 2 to 30 carbon atoms, a dialkylaminoalkylene group having 3 to 30 carbon atoms, or a trialkylsilylalkylene group having 4 to 30 carbon atoms, and R １ , R ２ , R ３ At least one of M is a saturated or unsaturated alkyl group having 10 or more carbon atoms, １ is an atom in group 15 of the periodic table.)

2. 2. The organically modified clay particles according to claim 1, wherein the difference between the median diameter and the mode diameter is within a range of ±5 μm.

3. 2. The organically modified clay particles according to claim 1, further comprising pyrophosphate and / or etidronate as inorganic salts.

4. 4. The organically modified clay particles according to claim 3, wherein the inorganic salt is contained in an amount of 0.1% by weight to 10% by weight.

5. An activator for a polymerization catalyst, comprising the organically modified clay particles according to claim 1.

6. 6. The polymerization catalyst activator according to claim 5, which is an activator of a transition metal compound for use in a single-site polymerization catalyst.

7. A transition metal compound represented by the following general formula (2) or (3): 【Chemistry 2】 【Chemistry 3】 [In the formula, M2 and M3 are titanium atoms, zirconium atoms, or hafnium atoms; each X is independently a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkylamino group having 1 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an alkoxyalkylene group having 2 to 20 carbon atoms, a dialkylaminoalkylene group having 3 to 20 carbon atoms, or a trialkylsilylalkylene group having 4 to 20 carbon atoms; R4 and R5 are cyclopentadienyl groups represented by the following general formula (4) or indenyl groups represented by the following general formula (5), 【Chemistry 4】 【Chemistry 5】 (In the formula, R9 to R12 and R13 to R18 each independently represent a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, an alkylamino group having 1 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an alkoxyalkylene group having 2 to 20 carbon atoms, a dialkylaminoalkylene group having 3 to 20 carbon atoms, or a trialkylsilylalkylene group having 4 to 20 carbon atoms.) R3 and R8 are an indenyl group represented by the above general formula (5) or an aryl fluorenyl group represented by the following general formula (6), 【Chemistry 6】 (In the formula, R19 to R26 each independently represent a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, an alkylamino group having 1 to 20 carbon atoms, an arylamino group having 6 to 30 carbon atoms, an arylalkylamino group having 7 to 30 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an alkoxyalkylene group having 2 to 20 carbon atoms, a dialkylaminoalkylene group having 3 to 20 carbon atoms, or a trialkylsilylalkylene group having 4 to 20 carbon atoms.) R6 is a crosslinking unit of R4 and R7 represented by the following general formula (7) or the following general formula (8), 【Chemistry 7】 【Chemistry 8】 (In the formula, R27 to R28 and R29 to R30 each independently represent a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 30 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an alkylamino group having 1 to 20 carbon atoms, an alkylsilyl group having 1 to 20 carbon atoms, an alkoxyalkylene group having 2 to 20 carbon atoms, a dialkylaminoalkylene group having 3 to 20 carbon atoms, or a trialkylsilylalkylene group having 4 to 20 carbon atoms; and M4 represents a silicon atom, a germanium atom, or a tin atom.) and l is an integer from 1 to 5. A catalyst for producing polyethylene, comprising the polymerization catalyst activator according to claim 5 and an organoaluminum compound.

8. 8. The catalyst for use in polyethylene production according to claim 7, wherein the organoaluminum compound is at least one selected from the group consisting of trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-isopropylaluminum, tri-n-butylaluminum, tri-isobutylaluminum, and tri-tert-butylaluminum.

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